Senior Engineer - Core Design & Performance

We are Rolls‑Royce SMR and we’re doing something that’s never been done before. We’re revolutionising an industry. This is a legacy opportunity for those excited by such a challenge. The Core Design team is responsible for ensuring the SMR reactor core operates within defined safety limits while delivering optimal performance and economic efficiency. This includes supporting shutdown margins, DNBR limits, fault response, fuel‑cycle optimisation and load‑following capability.

As a Senior Engineer – Core Design and Performance, you will play a critical role in the development, analysis and performance substantiation of the SMR reactor core. You will develop and apply neutronic and/or thermal‑hydraulic models to assess core behaviour across steady‑state operation and transient conditions, supporting both design development and safety case justification. Your work will underpin environmental, safety, security and safeguards (E3S) requirements, as well as plant performance and economic outcomes. You will contribute to the development of analysis methodologies and tools, including verification, validation and uncertainty quantification approaches. The role will also involve investigation of core‑related fault scenarios, supporting robust safety cases and regulatory engagement. Working within a multidisciplinary environment, you will collaborate closely with engineering, safety and performance teams to deliver integrated solutions, while managing interfaces and contributing to programme delivery.

Responsibilities

• Develop and refine neutronic and/or thermal‑hydraulic models of the reactor core
• Deliver technical analysis across core physics, kinetics and thermal‑hydraulics disciplines
• Assess steady‑state and transient core performance, ensuring compliance with safety limits
• Support evaluation of core‑related fault sequences and plant behaviour under fault conditions
• Develop and implement methodologies for core analysis and modelling
• Establish verification, validation and uncertainty quantification requirements for analytical models
• Produce high‑quality technical assessments supporting safety, environmental and economic performance
• Deliver work packages in line with programme governance, including planning, risk management and reporting
• Develop integrated task plans and manage risks, issues and opportunities
• Monitor progress and report against technical and programme milestones
• Engage with internal stakeholders, customers and regulators to resolve technical queries
• Manage interfaces with other engineering functions across the SMR programme
• Ensure compliance with nuclear safety, export control and regulatory requirements
• Support and mentor junior engineers, providing technical guidance and coaching

Key Skills Required

• Strong experience in reactor physics and/or thermal‑hydraulics analysis
• Understanding of pressurised water reactor (PWR) design, plant behaviour and operating principles
• Knowledge of nuclear safety case development, regulatory practices and E3S principles (including ALARP and BAT)
• Experience with analysis tools for core physics, kinetics or sub‑channel analysis
• Experience developing or using analysis tools such as CMS, VIPRE, CTF, S5 or similar (or equivalent transferable tools)
• Experience in developing pre‑ and post‑processing tools, ideally using Python
• Understanding of software development processes and quality assurance frameworks
• Proven ability to deliver complex technical work packages to time, cost and quality
• Strong planning and organisational skills, with ability to manage dependencies and priorities
• Ability to identify and manage technical risks and drive resolution
• Strong technical writing and communication skills, including engagement with stakeholders
• Experience working collaboratively across multidisciplinary engineering teams
• Ability to coach, mentor and support the development of junior engineers

Qualifications

• A strong academic background with a Master’s degree in Nuclear Engineering, Physics or a closely related discipline
• Typically 5+ years’ experience in reactor physics and/or thermal‑hydraulics analysis
• Experience in analysis scripting or data processing tools (e.g. Python)

Location

Hybrid working with one of the following as your primary site: Derby, Manchester or Warrington.

Salary And Package

The salary band for this role will be between £53,700 – £70,500 dependent on the skills, values and knowledge you bring. There may be flexibility in exceptional cases, and the role may develop further as the programme grows.

Benefits Include

• Bonus – Performance‑related target opportunity up to 12.5%
• Benefits Allowance – £2,200 per annum for a bespoke package
• Pension – 12% employer and 6% employee contributions
• Holidays – 28 days (+ public holidays) with the ability to buy or sell up to 4 days
• Private Medical Insurance – BUPA single cover
• Life Assurance – 6× pensionable pay
• Home Office Support – £250 one‑off payment for new starters

Selection Process

The closing date for this role is 7th June 2026. The process will begin with an introductory call with the Talent Acquisition Partner, with interviews being able to take place straight away.

Why Join Us?

You’ll be joining a forward‑thinking organisation that values transparency, fairness, and innovation. We offer:

• A flexible, inclusive, and supportive working environment.
• Opportunities for career growth in a rapidly scaling business.
• A culture that values diversity, innovation, and continuous learning.

We are an equal opportunities employer and welcome applications from all backgrounds. Inclusivity is important to us, and as a Disability Confident organisation, we are committed to fair, supportive, and continually improving recruitment practices that ensure everyone has the opportunity to thrive.

Also, if you are considering a career move or a sector-jump, please get in touch – we welcome applications from people with transferable skills.

Our Application Process

Due to the safety regulations within the nuclear industry, applicants will be required to participate in additional screening. These are:

• Obtaining Baseline Personnel Security Standard (BPSS) clearance
• Satisfactory completion of a Disclosure and Barring Service (DBS) check
• Satisfactory completion of a basic financial probity check